Poster frame



FIG. 1 is a front elevational view of a poster frame showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left-side elevational view thereof;

FIG. 4 is a right-side elevational view thereof;

FIG. 5 is a top plan elevational view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines are for environmental purposes only and form no part of the claimed design. 

The ornamental design for a poster frame, as shown and described. 